<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button>点击</button>
    
    <button id ="f">前进</button>
    <button id ="b">后退</button>
    <div>

    </div>
    <script>
        var f= document.querySelector('#f')
        var b= document.querySelector('#b')
        f.addEventListener('click',function(){
            history.forward()
        })
        b.addEventListener('click',function(){
            history.back()
        })
var btn=document.querySelector("button");
var div =document.querySelector("div");
btn.addEventListener("click",function(){
    console.log(location.href);
    location.href="http://www.baidu.com"

})
var timer =5;
setInterval(function(){
    if (timer==0){
        location.href="http://www.baidu.com"
    }
    else{
        div.innerHTML='你将在'+timer+'秒钟后跳转到首页';
        timer--;
    }
},1000)

    </script>
</body>
</html>